During this campaign season, many have argued (ourselves included) that sleep deprivation explains Donald Trump’s behavior as well as anything does. But, while the GOP front-runner is a sexist, batty bombast with the ethical rigidity of a water-logged gummy bear, he isn’t politically conservative in the traditional sense, and neither are his supporters. Ideologically, he’s a man of the people — well, he’s whatever man a reactionary, fickle people demands at the moment. He’s a shape-shifter; the non-solid, non-liquid diet prescribed to people without teeth. (At least we can count on Yogurt to expire by summer.)

Ted Cruz, however, is an ultra-conservative ideologue through and through. And his real supporters (that is, people who like him because they share his vision, not because he’s “anyone but Trump”) similarly epitomize the far-right mindset. Cruz, as many have noted, capitalizes on apocalyptic fear. He appeals to people who, like him, appear to see fire, brimstone, fetal pain and big bad government at every turn.

Though we don’t have any concrete reason to believe that Cruz rejects rest like Trump does, sleep deprivation could conceivably underlie he and his supporters’ Debbie Downer-ism. Or, it’s possible that Cruz and his base unconsciously process the world in a way that predisposes them to Tea Party political leanings. Why? Both sleep deprivation and political conservatism have been linked to negativity bias, a psychological phenomenon describing a tendency to pay disproportionate attention to negative cues in the environment.

Both sleep deprivation and political conservatism have been linked to negativity bias, a psychological phenomenon describing a tendency to pay disproportionate attention to negative cues in the environment.

Sleep-deprived people, research has shown, exhibit a stronger negativity bias than those who log sufficient sack-time. And, a team of political scientists and psychologists at the University of Nebraska recently found a link between political conservatism and negativity bias. In fact, their study, to be published in the journal Behavioral Brain Research, suggests that the more politically conservative someone is, the stronger their negativity bias will be.

Researchers can measure negativity bias in a number of ways. Studies have shown that sleep-deprived people are more likely than well-rested people to interpret a neutral face as projecting a negative emotion. Or, researchers might see which stimuli (sights, sounds, smells) grab someone’s attention. So, for example, do you set foot in your apartment and notice the neatly folded stack of clean laundry or the dusty tabletop beneath it?

In the current study, the Nebraska team tested college students’ memory for images that depicted emotionally positive, negative or neutral scenes, predicting that conservative participants would recall negative images most easily. Previous studies on both bias and political ideology informed their hunch. Other research, study authors wrote in their paper, has shown that people have an easier time recalling stimuli to which they initially pay most attention, which makes visual memory tasks good measures of attentional bias. Additionally, studies have shown that conservatives tend to fixate on negative pictures more quickly, and dwell on them longer, than liberals do.

The experiment was simple: Sixty-four participants spent seven minutes studying 144 images, each of which had been classified as positive, neutral or negative. Positive images mainly showed babies (human and animal) and pretty landscapes. Neutral scenes included snapshots of furniture and “less-common objects such as an extension cord and analog antenna.” And negative scenes came in four subcategories: snakes, spiders, scenes depicting human rights violations and scenes depicting animal mistreatment.

Then, participants viewed a larger group of 240 images, half of which they’d studied and half of which were new. For each photo, participants indicated whether they’d already seen it or not. Participants who fell right-of-center (based on a standardized measure of political ideology) identified previously seen negative scenes with more accuracy than positive or neutral ones. Superior memory for negative versus positive scenes, in fact, increased as political beliefs got Cruz-ier.

Researchers re-analyzed the results to make sure that conservative participants had a heightened recollection for all negative images, rather than for one subtype (e.g., snakes) or, more generally, for any high-arousing image, negative or positive. The negativity-conservatism bias persisted.

In the paper, they proposed several explanations to explain the link — here are three interesting theories:

Negativity bias informs social orientations that, in turn, shape political persuasion. Past research has shown that liberals and conservatives reliably differ on a number of personality traits and social perspectives, including openness to new experiences, conscientiousness, perceptions of human nature and tolerance for change and measures that increase equality. Could someone’s tendency to notice the negative underlie the whole lot?

They’re too emotional to handle a different point of view. The idea here is that conservatives have disproportionately intense responses to emotional events — so intense that it would be debilitating to form political beliefs that amplify those reactions. So, they endorse values that minimize their reactions. For example, former New York City Mayor Rudolph Giuliani’s efforts to “clean up the streets” by reducing the visibility of the city’s homeless population. Or, you know, give undocumented immigrants the boot. Out of sight, out of mind.

As of now, however, we don’t have an airtight explanation for the study findings, but we do have a link exemplified by Cruz, who bleeds panic and sweats peril. Fear, it seems, really is the mindkiller.